Baby number four will be joining older siblings, Mackynzie, Michael and Marcus, when he or she arrives next spring.

Meanwhile, another Duggar daughter, Jill, seems to be having a smooth, uneventful first pregnancy. While Jill is enjoying her first pregnancy, she and her husband Derick Dillard have hinted that unlike her parents Michelle and Jim Bob, they are open to the idea of adopting a baby one day, too.

"We're open to as many children as God will give us," Dillard told People Magazine in an interview back in October. "We believe children are a blessing from the Lord and a gift from him."

Dillard, 25, said the couple has discussed adopting a child too. "My mom was adopted," he added.

The 19 Kids and Counting reality star also dished on her pregnancy cravings. "I seem to be following my mom in that, like the dill pickle thing," she said. "In my first trimester it was everything cold because I had nausea. And then I just wanted everything salty, sour, cold."